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// See the LICENSE file in the project root for more information
// 
// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to you under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License. You may obtain a copy of the License at
// 
// http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// 

using log4net.Core;

namespace log4net.Util.PatternStringConverters
{
    /// <summary>Writes a newline to the output</summary>
    /// <remarks>
    /// <para>
    /// Writes the system dependent line terminator to the output.
    /// This behavior can be overridden by setting the <see cref="PatternConverter.Option"/>:
    /// </para>
    /// <list type="definition">
    ///   <listheader>
    ///     <term>Option Value</term>
    ///     <description>Output</description>
    ///   </listheader>
    ///   <item>
    ///     <term>DOS</term>
    ///     <description>DOS or Windows line terminator <c>"\r\n"</c></description>
    ///   </item>
    ///   <item>
    ///     <term>UNIX</term>
    ///     <description>UNIX line terminator <c>"\n"</c></description>
    ///   </item>
    /// </list>
    /// </remarks>
    /// <author>Nicko Cadell</author>
    internal sealed class NewLinePatternConverter : LiteralPatternConverter, IOptionHandler
    {
        /// <summary>Initialize the converter</summary>
        /// <remarks>
        /// <para>
        /// This is part of the <see cref="IOptionHandler"/> delayed object
        /// activation scheme. The <see cref="ActivateOptions"/> method must 
        /// be called on this object after the configuration properties have
        /// been set. Until <see cref="ActivateOptions"/> is called this
        /// object is in an undefined state and must not be used. 
        /// </para>
        /// <para>
        /// If any of the configuration properties are modified then 
        /// <see cref="ActivateOptions"/> must be called again.
        /// </para>
        /// </remarks>
        public void ActivateOptions()
        {
            if (SystemInfo.EqualsIgnoringCase(this.Option, "DOS"))
            {
                this.Option = "\r\n";
            }
            else if (SystemInfo.EqualsIgnoringCase(this.Option, "UNIX"))
            {
                this.Option = "\n";
            }
            else
            {
                this.Option = SystemInfo.NewLine;
            }
        }
    }
}
